The inorganic nutrients of most relevance in Spirulina are iron, calcium and phosphorous. People who tend to consume a great number of fiber foods which contain phytates and oxalates which, in turn, lower the bioavailability of iron in vegetables.
Spirulina could be able to counteract these two aspects: a) its iron content is substantially high: comparatively, cereals –which are usually considered good sources of iron– contain between 150-250 mg/kg; blue-green algae contains about 580-1800 mg/kg; b) algae does not have pericardium (as cereals do), hence it does not present phytates/oxalates that could chelate iron and lower its absorption (this is what happens, for example, with spinach).
The relative proportion (Ca:P) of these micronutrients is compatible
with the preservation of bone health since it reduces
the decalcification risk. Moreover, as it was previously
stated, the cyanobacterium of interest is an oxalate-free
plant food, thus –as with iron- it provides calcium
with high availability, thus it improves its absorption.